Until the present time, radial stackers employed in the mining and aggregate industry generally, required manual operation for all or part of their movements. However, in order to reduce the need for skilled manpower, it has long been desired to develop a control apparatus for such radial stackers which is totally automated and trouble free so that manpower problems could be reduced.
The prior art control apparatus for such radial stackers typically included a plurality of limit switches or probes. However, it has been found through experience that such limit switches freeze or become inoperable in cold or wet weather. As a result, radial stackers employing such limit switches or probes have a high amount of downtime and require a great deal of maintenance and repair work. In addition, such systems require constant surveillance by one or more operators, and this has become a problem as a result of shortages of skilled manpower.
Broadly, it is an object of the present invention to provide improved control apparatus for controlling the operation of a radial stacker which overcomes one or more of the aforesaid problems. Specifically, it is within the contemplation of the present invention to provide improved control apparatus for completely and automatically controlling the load-out cycle of a radial stacker and which does not require manpower to monitor the operation of same. At the completion of the loadout cycle, the operation of the radial stacker is automatically stopped, and an alarm is initiated to indicate the completion of the cycle.
It is a further object of the present invention to provide an improved control apparatus for controlling the operation of radial stackers which includes a plurality of presettable timers for controlling the horizontal and vertical movements of the radial stacker, in combination with suitable programmers for controlling the sequence of the timers.